Boxing promoter Eddie Hearn is already plotting a mega showdown between the two biggest stars in British boxing, but Joseph Parker could prove the ultimate spoiler.

The Kiwi WBO heavyweight champion is set to face Hearn's prized possession, Anthony Joshua, in a unification bout on April 1 (NZT) in Cardiff.

The fight isn't official yet, but with Joshua's promoter, David Higgins, currently in London finalising the deal and Parker set to arrive on the weekend, an announcement is imminent.

Joshua, who will put his IBF and WBA titles on the line against Parker, has often pined for a shot at former champion Tyson Fury - a fight that Hearn said he wants to start negotiating immediately, despite not having confirmed the bout with the Kiwi.

"I'll make one thing clear - we are happy to enter negotiations to fight Tyson Fury now," Hearn told IFLTV.

"We are happy to fight Tyson Fury in the summer, autumn or winter of 2018, but we can't base our career on someone that isn't fit, doesn't have a licence, hasn't boxed in two years and has pulled out of the last two fights.

"We don't need to. He needs to show less talk and more action."

Eddie Hearn
Photo credit: Getty

Hearn said Joshua's immediate focus is on beating Parker, as the first part of a 2018 where he intends establishing himself as the most dominant boxer since the Mike Tyson era.

WBC champion Deontay Wilder is likely to follow for the Brit, should he get past the Kiwi, with the year concluding in a box office bout against Fury.

But the problem for Hearn and Joshua is that Parker holds the same dreams, and the Brit may be in danger of looking past the undefeated New Zealander.

Joseph Parker is undefeated as a professional.
Photo credit: Getty

Hearn said that's not the case, but he must work on the future so his client can fulfil his legacy.

"He [Joshua] wants all the belts and, ultimately, I have the responsibility to chase that dream for him. If we beat Joseph Parker, then we only have one belt to go.

"This Parker fight will mean, after 21 fights, he has had two unification fights for the heavyweight world championship - he is running from no one, he will fight everybody."

Hearn had meetings with Higgins as late as Wednesday night (NZT) and confirmed that the paperwork is almost out of the way.

"My man David Higgins - he's a bit nuts, David Higgins, but he's a good guy," Hearn said. "He knows what he wants and we're moving at speed.

"We had about four hours yesterday, we're drafting, we've overcome most of the points in the agreement.

"Hopefully, Parker will come in the weekend... hopefully, you'll get an announcement next week."

Joseph Parker is expected to arrive in the UK as early as Saturday (NZT).